<i>N</i>-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1<i>H</i>-pyrazol-4-yl)acetamide–naphthalene-2,3-diol (1/1)

In the reaction of naphthalene-2,3-diol and 4-amino-anti-pyrine in the presence of acetic acid, the amine function is acetyl-ated and the resulting acetamide co-crystallizes with the diol in the title compound, C(13)H(15)N(3)O(2)·C(10)H(8)O(2), with 1:1 molar stoichiometry. The two components are linked by two O-H⋯O=C hydrogen bonds. One of the hy-droxy groups inter-acts with the pyrazolone carbonyl O atom and the other hy-droxy group inter-acts with the amide O atom of another component, generating a chain motif. Adjacent chains are linked into a layer motif via N-H⋯O inter-actions involving only the heterocyclic acetamide component.